The present invention relates to a reed relay and a method of making the same. It has been known heretofore to produce reed relays built up from so-called reed switches in many different ways, for example by inserting the glass tube enclosing a vacuum and a contact pair sealed therein and thus constituting a reed switch into a shrink-on hose, together with a coil winding surrounding the glass tube, and by forming from the latter, by a heating process and a clamping operation performed on both sides after hardening, the relay case which simultaneously serves to support the reed relay thus formed and to protect the glass tube.
There has been known still another method according to which the glass tube of the vacuum reed switch and the associated switching coil are introduced into a rectangular case with one open side wall, whereupon the case is hermetically sealed using a suitable synthetic resin, with the respective connection contacts projecting outwardly.
The known reed-relays therefore contain conventionally a coil support forming the coil and supporting at the same time the glass tube of the reed switch in such a manner that the contact reeds perform a movement during excitation, which means that the bobbin which is designed in one piece can act simultaneously as support for the coil and as casing for the reed switch so that it forms in this manner the entire reed relay.
Problems may, however, be encountered with the usual designs of reed relays and their production methods where such relays are intended for carrying currents or signals of particularly high frequencies (for example 30 MHz with currents of, for example, up to 5 A) or operating voltages which may, for example be in the range of kV.sub.SS. Such unusual and, therefore, extreme operating conditions may in the case of the usual reed relays lead to disadvantages due to the effect of the strong radio-frequency electromagnetic fields which lead at least to increased temperatures in the entire area of the coil and the relay so that apart from possible variations of the electric data, the stability of the reed relay itself may also be impaired.
Now, it is the object of the present invention to provide a production process for a reed relay, and a reed relay, wherein the detrimental effects (including the effects of high frequencies/high voltages/high currents) can be avoided by providing a particularly efficient low-ohmic shielding in the coil area.